feat(docs): Creates Asciidoctor constant extension (#148)

* feat(docs): Creates Asciidoctor constant extension

* chore: rename extension directory

.asciidoctor/lib/const-inline-macro.rb

@@ -0,0 +1,5 @@
+RUBY_ENGINE == 'opal' ? (require 'const-inline-macro/extension') : (require_relative 'const-inline-macro/extension')
+
+Extensions.register do
+  inline_macro ConstBlockMacro
+end

.asciidoctor/lib/const-inline-macro/extension.rb

@@ -0,0 +1,53 @@
+require 'asciidoctor/extensions' unless RUBY_ENGINE == 'opal'
+
+include ::Asciidoctor
+
+# A block macro that embeds a Constant into the output document
+#
+# Usage
+#
+#   const::src/main/java/org/superbiz/Color.java[name="DEFAULT_COLOR"]
+#   public static final String DEFAULT_COLOR = "blue";
+#
+#   const::src/main/java/org/superbiz/Color.java[tag="DEFAULT_COLOR"]
+#   // const::DEFAULT_COLOR[]
+#   public static final STRING MY_DEFAULT_COLOR = "blue";
+#
+class ConstBlockMacro < Extensions::InlineMacroProcessor
+  use_dsl
+  named :const
+
+  def process parent, target, attrs
+
+    data_path = parent.normalize_asset_path(target, 'target')
+    const_value = nil
+
+    if attrs.has_key? 'name'
+      const_name = attrs['name']
+
+      File.open(data_path).each do |line|
+        if (line[const_name])
+          # Gets content between double quotes
+          const_value = line.scan(/"([^"]*)"/)
+          break;
+        end
+      end
+    else
+      if attrs.has_key? 'tag'
+        const_tag = %(const::#{attrs['tag']})
+        found_tag = false
+        File.open(data_path).each do |line|
+          if found_tag
+            # Gets content between double quotes
+            const_value = line.scan(/"([^"]*)"/)
+            break;
+          end
+          if (line[const_tag])
+            found_tag = true
+          end
+        end
+      end
+    end
+    return const_value[0][0].chomp
+  end
+end

.travis.yml

@@ -31,7 +31,7 @@ env:
 script:
   - ./mvnw clean verify -P travis -DJAVA_OPTS="-XX:-UseLoopPredicate"
   - 'if [ $FORCE_DOC_GEN == 0 ] || [ $GENERATE_DOC == 0 ]; then
-        docker run -v $TRAVIS_BUILD_DIR:/docs/ --name adoc-to-html rochdev/alpine-asciidoctor:mini asciidoctor /docs/README.adoc -a generated-doc=true -a asciidoctor-source=/docs/docs -o /docs/gh-pages/index.html;
+        docker run -v $TRAVIS_BUILD_DIR:/docs/ --name adoc-to-html rochdev/alpine-asciidoctor:mini asciidoctor -r /docs/asciidoctor/lib/const-inline-macro.rb /docs/README.adoc -a generated-doc=true -a asciidoctor-source=/docs/docs -o /docs/gh-pages/index.html;
       fi'
 
 after_success: